Chronic, long-term Cannabis users and their closely matched non-user controls were compared during the transdisciplinary study carried out in 1973-1975 to determine the effects of long-term marihuana use. The present study proposes to re-locate-at least 85 percent of these same subjects to make possible intensive follow-up studies of some neuropsychological and psychosocial characteristics which might have changed in the intervening six to eight years since the previous study. The original study's fieldworkers will accomplish the proposed re-location by establishing contact with social network "brokers" who originally helped them to identify user and non-user samples. The project proposes not only to re-locate the original study subjects but to administer an interview schedule, eliciting follow-up information on drug use behavior, social status, health status, family stability, and work patterns for the purpose of comparisons with similar data elicited during the 1973-1975 study. Interview schedule results will test the amotivational syndrome hypothesis and also general hypotheses on health status differences or congruencies between user and non-user groups. The research team and consultants will also negotiate for the Costa Rica govrnment's cooperation in, and permission for the proposed intensive studies. Only successful re-location of subjects and negotiation of explicit governmental permissions will enable the funding for all the proposed intensive studies.